The first shrine at the site of the hot springs was built by Celts, and was dedicated to the goddess Sulis, whom the Romans identified with Minerva. Geoffrey of Monmouth in his largely fictional Historia Regum Britanniae describes how in 836 BC the spring was discovered by the British king Bladud who built the first baths. Early in the eighteenth century Geoffrey's obscure legend was given great prominence as a royal endorsement of the waters' qualities, with the embellishment that the spring had cured Bladud and his herd of pigs of leprosy through wallowing in the warm mud. Roman use The name Sulis continued to be used after the Roman invasion, leading to the town's Roman name of Aquae Sulis (literally, "the waters of Sulis"). The temple was constructed in 60-70 AD and the bathing complex was gradually built up over the next 300 years. During the Roman occupation of Britain, and possibly on the instructions of Emperor Claudius,engineers drove oak piles to provide a stable foundation into the mud and surrounded the spring with an irregular stone chamber lined with lead. In the second century it was enclosed within a wooden barrel-vaulted building,and included the caldarium (hot bath), tepidarium (warm bath), and frigidarium (cold bath). After the Roman withdrawal from Britain in the first decade of the fifth century, these fell into disrepair and were eventually lost due to silting up and flooding.